Theory Versus Experiment for the Rotordynamic Characteristics of a High Pressure Honeycomb Annular Gas Seal at Eccentric Positions

Abstract

Test results for leakage and rotordynamic coefficients are presented for a honeycomb-stator/smooth-rotor annular seal for eccentricity ratios out to 0.5 using air as the test fluid. Tests were conducted at supply pressures up to 70 bars and running speeds up to 20200 rpm. The seal has a diameter of 115 mm, a cell width of 0.79 mm, and a cell depth of 3.10 mm. Tests were conducted for the back-pressure ratios of 0.35, and 0.5. Comparisons are made to predictions from an analysis due to San Andres. The test results show a minimal sensitivity of either leakage or rotordynamic coefficients to changes in the eccentricity ratio. The predictions generally agree well with measurements.